Abstract: A transistor device having fin structures, source and drain terminals, channel layers and a gate structure is provided. The fin structures are disposed on a material layer. The fin structures are arranged in parallel and extending in a first direction. The source and drain terminals are disposed on the fin structures and the material layer and cover opposite ends of the fin structures. The channel layers are disposed respectively on the fin structures, and each channel layer extends between the source and drain terminals on the same fin structure. The gate structure is disposed on the channel layers and across the fin structures. The gate structure extends in a second direction perpendicular to the first direction. The materials of the channel layers include a transition metal and a chalcogenide, the source and drain terminals include a metallic material, and the channel layers are covalently bonded with the source and drain terminals.

Abstract: A method includes forming a first low-dimensional layer over an isolation layer, forming a first insulator over the first low-dimensional layer, forming a second low-dimensional layer over the first insulator, forming a second insulator over the second low-dimensional layer, and patterning the first low-dimensional layer, the first insulator, the second low-dimensional layer, and the second insulator into a protruding fin. Remaining portions of the first low-dimensional layer, the first insulator, the second low-dimensional layer, and the second insulator form a first low-dimensional strip, a first insulator strip, a second low-dimensional strip, and a second insulator strip, respectively. A transistor is then formed based on the protruding fin.